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Atlantic Bluefin Tuna - The Facts

09 August 2019

Atlantic Bluefin Tuna - The Facts

Press Release 9th August 2019

The Gibraltar Chronicle published an opinion piece by Mr. Samuel Marrache on the 6th August titled “Dispelling the myths about Atlantic Bluefin Tuna (ABT) fishing in Gibraltar”. This piece came in response to a joint statement issued by The Nautilus Project (TNP) and the Gibraltar Ornithological and Natural History Society (GONHS), which called for the Government to reconsider and remove ABT landings altogether.
The opinion piece contains errors that need correcting publicly.  GONHS (as an IUCN member) and TNP have collaborated in their joint response.

1. International Union for the Conservation of Nature (IUCN) Endangered status
The organisations have correctly cited IUCN, which states that Atlantic Bluefin Tuna (Thunnus thynnus) is listed as “Endangered” within the Mediterranean. This status implies that a species ”faces a high risk of extinction in the near future”, with the assessment for the species stating that it “has become rare relative to historical levels because of massive overfishing” (IUCN Red List, Faillettaz et al. 2019). Mr Marrache’s article states that ABT are “nowhere near critically endangered”. Neither GONHS nor TNP have ever said that the species is listed as critically endangered.
The IUCN, of which the Department of the Environment, Heritage and Climate Change (DEHCC) is also a member, is the globally recognised authority on these matters. It uses available scientific peer-reviewed papers as the basis for its assessments.
The author references Species+ incorrectly, as Species+ is an online search engine for species listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which is a HM Customs issue and not relevant to fishing within our waters. In any case, the IUCN has been pushing for ABT to be included in CITES Appendix 1, which if included, would make international trade illegal.
2. The article claims that the endangered status is due to historic overfishing and that recent ICCAT data since 2010 claims that ABT have been on the rise since 2010.
ICCAT is a management body which is in place to regulate the fisheries of about 30 species. It considers the latest scientific peer-reviewed papers in its conferences, but there is evidence that it has historically ignored scientific advice due to political pressures (Gager et al. 2011).
ICCAT data is not submitted to a scientific journal nor are its papers peer-reviewed. Consequently, criticising the IUCN-assigned status as “outdated” whilst quoting ICCAT figures is unjustified at best.
The article negates to include sources for its assertion that stocks have been increasing since 2010. The IUCN states that ABT populations are “decreasing” in the Mediterranean (Di Natale et al. 2011) and until new data become available, the precautionary principle must be adhered to.  Anecdotal views are offered to support the view that numbers are increasing due to “magnificent conservation efforts of the past few years”, but a very recent scientific paper suggests that little is known about ABT abundance and spatial distribution (Faillettaz et al. 2019).
Total allowable catches (TACs) have been rising since 2010 as evidenced in 2nd ICCAT Performance Review report 2016. By 2017 the TAC was at around 22,500 tonnes, already beginning to approach the 2006 TAC of 32,000 tonnes, when ICCAT was forced to drop the quota because it was unsustainable.
3. Gibraltar quota assignment
Indeed, ICCAT quotas are not assigned on a per capita basis and yet they are not assigned by access to ABT either, as stated in the opinion piece. And surely, number of potential consumers is a more useful metric than number of potential fishermen, as it is market forces that are endangering the species. Currently, ICCAT uses size-structured population models to calculate the probability that, at a given catch quota, the stock recovers to maximum sustainable yield (MSY) levels by the year 2022. Quotas are set at the highest level of catch that would still allow a 60% (or higher) probability of recovery (Gagern et al. 2011). However, models do not include illegal catch which accounts for up to 57% on top of the set ICCAT quota, and ICCAT routinely sets quotas that exceed scientifically quantified recommendations (Gagern et al. 2011).  Against this background, Gibraltar’s quota is still extremely high when compared to ICCAT quotas for other countries, by any sensible measure.
4. Locally supplied tuna is better than Spanish bought tuna
The local sale of ABT is rampant, with people advertising it on Facebook and frequent sale by local restaurants. What would be ICCAT’s view on this?  Quoting ICCAT REC 17-07, Part II - Management Measures, Recreational fisheries and sport fisheries, “32. The marketing of bluefin tuna caught in recreational and sports fishing shall be prohibited.”. Is the answer now that Gibraltar doesn’t form part of ICCAT, whilst simultaneously using ICCAT’s quotas to justify our own?
5. Tuna fishermen don’t make good money from the sport
During the 2017 New Year Auction at Tokyo’s Tsukiji market, a 405Kg ABT was sold for $320,000 (£263,000). In the same market in 2013, a restauranteur paid £43,000 for a 230Kg ABT.
In Spain in 2013, a farmed, 184Kg ABT was sold for £5,200. These are not Tokyo prices, but they are tax free.
Finally, the amount of money spent by fishermen for recreational activities is not a factor that can be considered when planning the conservation of an endangered species.  Nor are we calling for such equipment to be discarded: GONHS has in the past called for a shift from killing ABT to tag-and-release for research purposes, which could still be carried out by local fishermen.  Both organisations continue to call for this.

DI NATALE, A. 2011. ICCAT GBYP. Atlantic-wide Bluefin Tuna Research Programme 2010. GBYP Coordinator Detailed Activity Report for 2009-2010. Collect. Vol. Sci. Pap. ICCAT, 66, 995-1009.
FAILLETTAZ, R., BEAUGRAND, G., GOBERVILLE, E. & KIRBY, R. R. 2019. Atlantic Multidecadal Oscillations drive the basin-scale distribution of Atlantic bluefin tuna. Science advances, 5, eaar6993.
GAGERN, A., VAN DEN BERGH, J. & SUMAILA, U. R. 2013. Trade-based estimation of bluefin tuna catches in the Eastern Atlantic and Mediterranean, 2005–2011. PloS one, 8, e69959.
IUCN Red List. Available: Https:// [Accessed 08/08/19 2019].